1. Field of the Invention
This invention relates to hinge mechanisms and particularly to a new and improved motor driven hinge assembly which provides reversible hinge motion with high mechanical advantage.
2. Description of the Prior Art
In certain situations, it is desirable to have self-powered hinge mechanisms to fold or unfold hinged members. For example, large space structures comprising multitubular frames are folded prior to their launch into space in order to fit in the launch vehicle and then are unfolded during their deployment in space. The hinged tubular members comprising the frames must have the capability of unfolding upon remote command in such a space environment. Furthermore, the self-powered hinge mechanisms which unfold the frames must be compact so as to not use up scarce room in the launch vehicle yet the mechanisms must exert sufficient force and have enough mechanical advantage to unfold the hinged members of the frame.
One suitable mechanism to provide self-powered unfolding of the tubular members is a spring powered hinge. Spring powered hinges, however, operate in only one direction and are therefore not capable of folding the members, should that become necessary. It may be desirable, for example, to retrieve a large space structure from space. To do so would require folding the frames of the structure in order to fit the structure into the retrieving vehicle. A separate drive mechanism would be required to overcome the force of the spring powered hinges in order to fold the frames, thus increasing weight, complexity and cost.
Another shortcoming of spring powered hinges is that only two pivotal positions of the hinged members are available, folded and unfolded. The spring mechanism does not provide selectable intermediate pivotal positions between the folded and unfolded positions.
In view of the above mentioned problems, it is therefore an object of the present invention to provide a motor driven hinge assembly which not only can unfold but which can also fold hinged members as desired.
Another object of the present invention is to provide a motor driven hinge assembly which permits hinged members to be pivotally positioned at numerous positions intermediate the folded and unfolded positions.
Yet another object of the present invention is to provide a motor driven hinge assembly which is compact yet which has a high mechanical advantage.